August 14th NE Blackout and Common Roots of Blackouts

Damir Novosel, PhDPresident

KEMA Inc., T&D Consultingdnovosel@kema.com

BLACKOUT AMERICANO E ITALIANO:

LUNEDÌ, 10 MAGGIO 2004ROMA

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System Blackouts: Description and Prevention

1. US Grid

2. Descriptions of the August 14th NE Blackouts

3. Common Roots of Blackouts

4. Conclusions

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The US at night: the transmission grid

Sparse load:

Sparse network

Dense load:

Dense network

140 GW 650 GW

60 GW

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Areas of retail competition

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Regional reliability coordinators

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Reliability coordinators & control areas:Complexity

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Regional Councils and NE Blackout Effects

ASCC

Blackout Area

August 14, NE USA (8 states) and Canada (2 provinces) affected: 50 million people 34,000 miles of transmission ~290 Generating units ~61,800 MW Restoration efforts

A day to restore power to NY City

Two days to restore power to DetroitRegional Councils

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14 August temperatures

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10:05:44 Conesville Unit 5 375 MW

1:14:04 Greenwood Unit 1785 MW

1:31:34 Eastlake Unit 5597 MW

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Aug. 14th NE Blackout: Initial Generator Outages

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2,200 MW Power Reversal to Northern Ohio overloading the lines and causing voltage to decline

2:02 Stuart-Atlanta 345kVtrips due to a fault

3:05 Harding-Chamberlain 345 kV sags into a tree

3:32 Hanna-Juniper 345kV sags into a tree, other 345 kV lines disconnect => 16 of 135kV lines overload and trip

4:06 Sammis-Star 345kVtrips on overload

4:09 Galion-Ohio 345kVCentral-Muskingum

4:09 East Lima-Fostoria 345kV

August 14th Blackout – Some Key Events4

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20 Generators around Lake Erie (app. 2,174 MW) tripped

Michigan lines trip

1256 MW Generator trips

Transmission system separation

Another power reversal, power flow (2,800 MW) to Northern Ohio through Ontario and MichiganThe cascading events proceeded including apparent voltage decline.

August 14th Blackout - Some Key Events

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Cascading Failure Complete at 4:13 PM

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33 4:10:50 Ontario system separates from New York

4:10:43 Long Mountain – Plum Tree (345 kV Line)

4:10:45 Remaining lines between Ontario and Eastern Michigan separate

August 14th Blackout - Some Key Events

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NE Blackout - Cascading Failure Complete at 4:13

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August 14th Blackout - Power Plants Tripped

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August 14th Blackout Cascade Sequence

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Common Roots of Blackouts Caused by multiple contingencies

with complex interactions

Usually no “single” cause

Sequence of low probability events difficult to accurately predict

Practically infinite number of operating contingencies, different from the expectations of system designers

Operators cannot act fast enough for fast developing disturbances

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Pre-conditions and Factors for Blackouts Congested grid

No lines & generators in my backyard!

Not enough reactive support Tight operating margins, with less

redundancy Regulatory uncertainty Low level of investment

in recent years How and who to invest? How to recover costs?

The bulk power system was not designed to transfer large amounts of power, but to improve network security

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Pre-conditions and Factors for Blackouts Inadequate right-of-way maintenance

FE failed to adequately trim trees

Aging equipment, prone to failures Insufficiently coordinated equipment maintenance and

generation scheduling Weather (high temperatures; wind, thunderstorm, fog, etc.)

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How Do Disturbances Turn Into a Blackout?Cascading events that cause disturbances to propagate

Sequential tripping due to overloads, power swings, and voltage fluctuations

Protection involved in ~70% of blackout events in North America In some cases, protection miss-operation or unnecessary actions: incorrect

settings, uncovered application design flows, or HW failures

Inadequate or faulty EMS/SCADA system (alarm burst) E.g. FE lost its system condition alarm system around 2:14 pm MISO (FE’s reliability coordinator) had an unrelated software problem and

was unable to tell that FE’s lines were becoming overloaded Insufficient reactive support where and when required Inability of operators to prevent further propagation

Sacrifice own load or cut interties or get support from neighbors

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Contributing Factors that Allow Blackout to Spread Lack of coordinated response during developing disturbances

PJM saw the growing problem, but did not have joint procedures in place with MISO to deal with the problem quickly and effectively

Should we help or should we separate?

Inadequate planning/operation studies FE didn’t ensure the security of its transmission system because it didn’t

use an effective contingency analysis tool routinely

Lack of inadequate Special Protection Schemes to prevent spreading of the disturbance:

Prevent further overloading of the lines Arrest voltage decline Initiate pre-planned separation of the power system for severe

emergencies

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Conclusions North-American Grid not designed for large transfers

Increase in the number and frequency of major blackouts

Analysis of recent disturbances reveals some common threads among them, leading to conclusions that: Propagation can be arrested

Impact of disturbances/outages can be reduced

Various cures to reduce the possibility of future outages A need for deployment of well-defined and coordinated overall plans

(planning, operations and maintenance)